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United States Patent |
5,292,057
|
Lomastro
|
March 8, 1994
|
Fixture for, and method of, welding grounding connector to structural
steel member
Abstract
A fixture for welding a grounding connector to a structural steel member is
disclosed. Such fixture is formed of a magnetic material so that the
fixture is attracted to, and retained upon, the steel member. A chamber is
defined within the rectangular body of the fixture, and an inlet passage
in the front of the fixture receives one end of the grounding connector.
Thermite powder is introduced into the chamber, and an igniter cap
delivers a spark to the powder, to ignite same, thereby producing a molten
mass of metal. The metal flows the fixture and bonds the grounding
connector and the fixture to the structural steel member. The method of
utilizing such single-use fixture is also disclosed.
Inventors:
|
Lomastro; Joseph A. (Pawtucket, RI)
|
Assignee:
|
Burndy Corporation (Norwalk, CT)
|
Appl. No.:
|
016265 |
Filed:
|
February 11, 1993 |
Current U.S. Class: |
228/198; 228/4.1; 228/234.3 |
Intern'l Class: |
B23K 023/00 |
Field of Search: |
228/241,198,4.1
|
References Cited
U.S. Patent Documents
802967 | Oct., 1905 | Brown | 228/241.
|
878868 | Feb., 1908 | Cole | 164/54.
|
878869 | Feb., 1908 | Cole | 164/54.
|
1007005 | Oct., 1911 | Lukaszewske | 164/54.
|
2225028 | Dec., 1940 | Banks | 44/3.
|
2318604 | May., 1943 | Febrey | 228/241.
|
2383008 | Aug., 1945 | Meister | 269/8.
|
2482093 | Sep., 1949 | Carlson | 228/241.
|
2991347 | Jul., 1961 | Weinstein | 219/85.
|
3262163 | Jul., 1966 | Gelfand | 228/241.
|
4114262 | Sep., 1978 | Franck | 29/628.
|
4729503 | Mar., 1988 | Niinivaara | 228/241.
|
4822289 | Apr., 1989 | DeLeo | 439/92.
|
4887970 | Dec., 1989 | den Hartog | 439/92.
|
Primary Examiner: Ramsey; Kenneth J.
Attorney, Agent or Firm: Hoffman, Wasson & Gitler
Claims
I claim:
1. A fixture for forming a connection between a connector and a structural
steel member, said fixture comprising:
a) a body having a front wall, a rear wall, a pair of spaced side walls, a
top wall, and a bottom wall,
b) said body having a chamber formed therein,
c) said chamber opening upwardly through said top wall,
d) said chamber terminating in a channel at its lower end,
e) said body having an inlet passage extending inwardly, and upwardly, from
the front wall of the body,
f) an outlet defined through said rear wall of said body to communicate
with said channel,
g) a connector retained with said inlet passage in communication with said
channel and said outlet,
h) magnetic means for securing said fixture to said structural steel
member,
i) an ignitable substance introduced into said chamber, and
j) an igniter cap positioned over the open upper end of said chamber for
providing a spark to said ignitable substance which produces a molten
metal mass that flows through said channel and said outlet to bond said
fixture and said connector to said structural steel member.
2. A fixture as defined in claim 1 wherein said body is rectangular in
shape and is formed of a magnetic material that is attracted to said
structural steel member.
3. A fixture as defined in claim 1 wherein said ignitable substance is
thermite powder.
4. A method of using a fixture to form a connection between a connector and
a structural steel member, said fixture having a chamber formed therein,
the method comprising the steps of:
a) adhering said fixture to said structural steel member by magnetic
attraction,
b) inserting a connector into the interior of said fixture until said
connector establishes communication with said chamber,
c) introducing thermite powder into said chamber,
d) igniting said thermite powder to initiate an exothermic reaction that
produces a molten metal mass, and
e) permitting said mass to flow through said fixture to bond said connector
and said fixture to said structural steel member.
5. The method of claim 4 further including the steps of positioning an
actuator cap over said chamber, and then actuating said cap to produce a
spark for igniting said thermite powder.
Description
FIELD OF THE INVENTION
The invention relates to a fixture for welding a grounding connector to a
steel member, and the method of using such fixture to perform such welding
operation.
DESCRIPTION OF THE PRIOR ART
Relatively expensive molds have previously been used to weld grounding
cables to structural steel elements. Such molds have employed complex
mechanical clamping mechanisms to engage the structural steel member, and
to position the mold thereon. The molds are used several times, in order
to reduce the cost per molding operation. Difficulty may be encountered in
positioning, and then clamping the mold in position. Similarly, after the
welding operation has been completed, difficulty is encountered in
removing the mold from the area of the welded joint formed between the
grounding cables and the flat steel surface to which it is bonded. Such
molds are available from Erico Products, Inc., Cleveland (Solon), Ohio
44139.
SUMMARY OF THE INVENTION
The present invention provides an inexpensive, single use, fixture that
welds a grounding connector to a structural steel member. The fixture is
formed of a magnetic material that is attracted to, and retained upon, the
structural steel member, thus obviating the need for mechanical clamping
systems used with conventional molds used for similar purposes.
The present invention includes a fixture including a body with an interior
chamber adapted to receive thermite powder, and an igniter cap positioned
above the chamber. Thermite powder is a mixture of aluminum powder and ion
oxide, that, when ignited, evolves a great deal of heat, and is used in
welding. An inlet passage extends angularly upwardly from the front face
of the fixture, and one end of a grounding connector is inserted, and
retained, therein. A rectangular outlet is defined in the rear face of the
fixture. When the igniter cap is actuated to produce a spark, the thermite
burns very rapidly and produces a molten metal mass that bonds the
connector to the structural steel member. The fixture is also bonded in
fixed position on the structural steel member. A grounding cable, or
conductor, is secured to the connector to complete the connection.
The present invention contemplates a simple method of using the fixture to
produce a connection that is reliable and long-lived. The resultant
connection is equal, if not superior, to connections formed by known,
multiple use molds with complex mechanical clamping systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of a fixture
constructed in accordance with the principles of the present invention,
such fixture being used to weld a grounding stud to a structural steel
member;
FIG. 2 is a side elevational view of the preferred embodiment of the
fixture secured to the structural steel member, with a grounding stud
being inserted therein;
FIG. 3 is a rear elevational view of the preferred embodiment of the
fixture;
FIG. 4 is a side elevational view of an alternative embodiment of the
fixture secured to the structural steel member, with a grounding stud
being inserted therein; and
FIG. 5 is a rear elevational view of the alternative embodiment of the
fixture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, FIGS. 1-3 depict a preferred embodiment of the
fixture 10 constructed in accordance with the principles of the present
invention. Fixture 10 comprises a generally rectangular block 12 formed of
a magnetized steel material. A chamber 14 is formed within the body; such
chamber opens outwardly at the upper end of the body, and tapers inwardly
to terminate in channel 16 at its lower end. Channel 16 communications
with rectangular outlet 18, that opens through the rear face of block 12.
An angularly oriented, tubular inlet passage 20 extends inwardly, and
upwardly, from the front face of fixture 10. As indicated by the
directional arrow shown in FIG. 2, the leading end of a grounding stud 22
is inserted into the passage 20. The leading end establishes communication
with channel 16, when fully inserted. The overall configuration of
grounding stud 22 is shown in FIG. 1, while only a fragment of grounding
stud 22 is visible in FIG. 2. One grounding stud that is well suited for
use with fixture 10 is identified as the "G-stud", and is sold by the
Burndy Corporation of Norwalk, Conn.
A grounding conductor 24 is secured to the trailing end of stud 22 by a
compression ring 26. The compression ring is crimped radially by
conventional crimping tools, to mechanically, and electrically, join the
grounding conductor to the grounding stud. A cap 28 covers the open, upper
end of chamber 14 in fixture 10. The cap also functions as a spark
generator, for welding powders introduced into chamber 14.
Block 12 of fixture 10 is formed of a magnetic steel material; such
material enables fixture 10 to be affixed to the web 30 of a structural
steel member, such as an I-beam 32. Only a fragment of beam 32 is shown in
FIG. 1. The magnetized steel body insures that the fixture will be
retained, in fixed position, upon beam 32 without resort to mechanical
clamping mechanisms.
The method of utilizing fixture 10, to establish a secure connection
between grounding cable 24 and beam 32, via grounding stud 22, is
relatively simple to execute, yet efficient in operation. As the first
step, block 12 is positioned upon I-beam 32, at a desired location; the
block is retained in fixed position because of the magnetic attraction
between the block and the beam. Then, the leading end of conductor 22 is
inserted into inlet passage 20 in block 12. The conductor is retained in
position because of an interference fit between the conductor cable and
the inlet passage; the magnetized body may also attract the grounding
stud.
Thermite welding powder is then introduced into the upper end of chamber 14
and flows downwardly through channel 16 to surround the leading end of
conductor 22. Cap 28 is then positioned atop the open end of chamber 14,
and is then struck, twisted, or otherwise mechanically manipulated, to
produce a spark. The spark causes the powder to burn fiercely, and produce
an exothermic reaction that bonds the leading end of conductor 22 to block
12, which, in turn, is secured, magnetically, to beam 32. Fixture 10 is
also bonded to beam 32 by the flow of molten metal exiting through
rectangular outlet 18. The molten metal that effectuates these permanent
bonds is visible in FIG. 1, along the perimeter of block 12 adjacent to
beam 32.
ALTERNATIVE EMBODIMENT
FIGS. 4 and 5 depict an alternative embodiment of a fixture constructed in
accordance with the principles of the present invention. Fixture 50
comprises a generally rectangular block 52 formed of a magnetized steel
material. A chamber 54 is formed within the body; such chamber opens
outwardly at the upper end of the body, and tapers inwardly to terminate
in channel 56 at its lower end.
An angularly oriented inlet passage 58 extends inwardly, and upwardly, from
the front face of fixture 50. While passage 20 in fixture 10 is configured
to receive a grounding stud of cylindrical shape, passage 58 is configured
to receive the leading end, or tongue 60 of a conventional tongue
connector. Tongue 60, when fully inserted, establishes communication with
channel 56. The directional arrow in FIG. 4 suggests the path of movement
of tongue 60 within fixture 50.
A rectangular outlet 62 opens outwardly through the rear of fixture 50; the
outlet communicates with channel 56. A cap 64 covers the open, upper end
of chamber 54; the cap is an igniter, and, when actuated, ignites the
thermite powder introduced into chamber 54. The molten metal flows about
tongue 60, positioned within inlet passage 58, and bonds the tongue
connector to metal support member 66.
Other refinements, alterations, and modifications of fixtures 10 and 50 may
occur to the skilled artisan. For example, while the rear surfaces of
fixtures 10 and 50 are flat to fit snugly against I-beams, H-beams, or the
like, such rear surface may be curved if the fixture is to be used to
secure grounding connectors, tongue connectors, and the like, to curved
surfaces such as pipes or tubular elements. Also, the structural steel
elements might be replaced with steel components. The inlet passage in
fixtures 10 and 50 may be configured to received, and retain, a variety of
shapes, and sizes, of connectors. Consequently, the appended claims should
be liberally construed in a manner consistent with the spirit of the
invention, and should not be construed in accordance with their literal
terms.
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